Re: Is Vacuum Working ? - Mailing list pgsql-admin

From Tom Lane
Subject Re: Is Vacuum Working ?
Date
Msg-id 15866.1252076479@sss.pgh.pa.us
Whole thread Raw
In response to Is Vacuum Working ?  ("Thorne, Francis" <thornef@cromwell.co.uk>)
List pgsql-admin
"Thorne, Francis" <thornef@cromwell.co.uk> writes:
> Information in Log file after database restart

> 01/08/2009 - Next Transaction ID = 1400435363
> 01/09/2009 - Next Transaction ID = 1462025864

> Transaction_ID Wrapwround limit is 214784146 limited by database
> postgres

> Is this normal, I would have thought the transactional ID would have
> stayed roughly the same due to vacuum ? If this keeps increasing will it
> mean I am getting to close my 2 billion transaction limit ?

Yeah, this looks perfectly normal.  VACUUM doesn't make the next-XID
counter go backwards.  What it will do from time to time is push out the
wraparound limit (by "freezing" very old rows' XID numbers).  As long as
there's a few million transactions' worth of daylight between the wrap
limit and current XIDs, there's nothing to worry about.

            regards, tom lane

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